In a large skillet, heat the oil over medium heat. Add the lean ground beef and cook until browned, breaking it apart with a spatula. Drain excess fat if necessary. Stir in the taco seasoning and water, and let it simmer for about 5 minutes until the mixture thickens and is well combined.
Preheat your oven to 400°F (200°C). While the beef is simmering, warm the corn tortillas in a separate pan until they are pliable. This step is crucial as it helps prevent them from cracking when assembled.
On a baking sheet, place one tortilla as the base. Spread a generous layer of refried beans over the tortilla, followed by a layer of the seasoned beef mixture. Drizzle some red enchilada sauce over the beef for an extra kick.
Sprinkle a hearty amount of shredded cheddar cheese on top of the beef. Add another tortilla on top, and repeat the layering process with beans, beef, enchilada sauce, cheese, and finally, the top tortilla.
Once assembled, place the Mexican Pizza in the preheated oven and bake for about 10-12 minutes, or until the cheese is melted and bubbly.
Remove the pizza from the oven and let it cool for a minute. Top with diced Roma tomatoes, sliced olives, and chopped green onions. Slice into wedges and serve with your favorite toppings like sour cream or guacamole.
